Other

Polartechnics Limited

Andrew Batrac

Victor N Skladnev

Richard L Thompson

Stephen Rowe

Roger Caffin

Peter West

Scott Menzies

Hugues Talbot

Alex Gutenev

Leanne Bischoff

David Varvel

The present invention discloses methods for lossless shearing and/or rotation of two-dimensional (2D) data, including digital images, with minute discrete angular increments, carried out only by permutations in the Fourier frequency domain, by exploiting the natural shear occurring as a result of computing a single one-dimensional discrete Fourier transform (DFT) of 2D arrays. Rotations in general, especially for oblong arrays, occur on elliptical paths. Circular rotation, by an angle of arctan(1/width), is achieved on square arrays. When each dimension is multiple of a smaller N, the rotation/shear angle can be increased to arctan(2N/width). Rotation steps can be repeated in long, animation-like series, with neither loss nor degradation of the Fourier content; so much so that tracing the steps back does restore the original data with remarkable precision.

Method for lossless digital shearing and rotation with fine angular increments

A system for collecting, storing and displaying dermatological images for the purpose of monitoring and diagnosis of skin conditions and skin cancers, including melanoma. A hand-held unit illuminates a section of the patient's skin, and an imaging device generates imaging signals from light derived from a skin section. Pairs of light output ports in the hand-held unit are arranged such that their intensity distributions overlap at their half-intensity levels so that the resulting summation of their intensities has a flat central region. Three image stores are maintained, one for lesion images, one for 'nearby skin' images, and one for reference-white images. The 'nearby skin' images are used by the system software to automatically determine the skin/lesion border. The reference white images are used to set the dynamic range of the instrument and to compensate for lighting irregularities. Two images of the same lesion taken at different times may be displayed simultaneously so that changes in the lesion may be determined. The calibration system is designed so that image data taken on any of multiple machines built to the same specification will be corrected back to a common reference standard to ensure absolute accuracy in colour rendition.

System and method for examining, recording and analyzing dermatological conditions

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Dee Why, Australia

Andrew Batrac